You may add recognition ads to pages and then want to move them to a different page. This is how you can remove an ad which has been placed on a page.
1. Go to the page spread where the ad is placed. Select Ads.
2. Click on the ad and drag it to View Ads to the left. Now the ad can be added to a different page.
Note: Do not delete the page spread to remove an ad. When you delete the page spread, all of the ads will move to Unused and you will have to place them all on pages again.